Apolipoprotein CII (apoCII) is a protein found in large fat particles that the gastrointestinal tract absorbs. It is also found in very low density lipoprotein (VLDL), which is made up of mostly triglycerides (a type of fat in your blood).
This article discusses the test used to check for apoCII in a sample of your blood.
ApoCII; Apoprotein CII; ApoC2; Lipoprotein lipase deficiency - apolipoprotein CII; Chylomicronemia syndrome - apolipoprotein CII
How the Test is Performed
How to Prepare for the Test
You may be told not to eat or drink anything for 4 to 6 hours before the test.
How the Test will Feel
When the needle is inserted to draw blood, you may feel some pain, or only a prick or stinging. Afterward, there may be some throbbing where the needle was inserted.
Why the Test is Performed
ApoCII measurements can help determine the type or cause of high blood fats. It is not clear whether the test results improve treatment. Because of this, most health insurance companies will not pay for the test. If you DO NOT have high cholesterol or heart disease or a family history of these conditions, this test may not be recommended for you.
The normal range is 3 to 5 mg/dL. However, apoCII results are usually reported as present or absent.
The examples above are common measurements for results of these tests. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.
What Abnormal Results Mean
High levels of apoCII may be due to a family history of lipoprotein lipase deficiency. This is a condition in which the body does not break down fats normally.
ApoCII levels are also seen in people with a rare condition called familial apoprotein CII deficiency. This causes chylomicronemia syndrome, another condition in which the body does not break down fats normally.
Risks associated with having blood drawn are slight but may include:
- Excessive bleeding
- Fainting or feeling lightheaded
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
Apolipoprotein measurements may provide more detail about your risk for heart disease, but the added value of this test beyond a lipid panel is unknown.
Genest J, Libby P. Lipoprotein disorders and cardiovascular disease. In: Zipes DP, Libby P, Bonow RO, Mann DL, Tomaselli GF, Braunwald E, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 11th ed. Philadelphia, PA: Elsevier Saunders; 2018:chap 48.
Remaley AT, Dayspring TD, Warnick GR. Lipids, lipoproteins, apolipoproteins, and other cardiovascular risk factors. In: Rifai N, ed. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. St Louis, MO: Elsevier; 2018:chap 34.
Semenkovich, CF. Disorders of lipid metabolism. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 206.
Reviewed By: Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.